A common procedure in the medical field is drawing of blood/body fluid specimens from a patient for laboratory analysis to assist in diagnosing of the patient's medical symptoms. The use of a syringe and needle is commonly used by direct venepuncture, or with use of a central or established peripheral intraveneous line (IV). Direct venepuncture uses a syringe fitted with a sharp pointed needle for penetrating the body and insertion into a vein, artery, spinal column, or body cavity. Peripheral/Central intravenous lines are also accessed with a syringe and a sharp pointed needle. The syringe is screwed onto the hub of the intravenous line and blood is withdrawn. A sharp pointed needle is then attached. Operating the syringe in an extracting mode effects withdrawal of a quantity of blood/body fluids from the patient and it is temporarily stored in the syringe's tubular body. After drawing the desired quantity of blood, the health care worker then extracts the syringe and needle from the patient or unscrews the syringe from the hub of the central or peripheral intravenous line and attaches a needle in preparatory to transfer of the just drawn specimen to a blood/body fluid collection container. Blood/body fluid collection containers are of tubular configuration provided at their open end with a closure that is gas impermeable although, in accordance with prior art, it is puncturable by the sharp-pointed end of a needle.
It is desirable that the closure member be gas impermeable, as is the collection container, since the collected blood/body fluid specimen is preferably stored in a closed container from which ambient air has been evacuated. Thus, a collection container, prior to receiving a blood/body fluid specimen, is essentially an empty void representing a vacuum. Ambient air contains or carries oxygen, carbon dioxide, nitrogen and other gaseous materials in addition to particles of various solid substances, all of which tend to contaminate the blood/body fluid specimen. Consequently, a blood/body fluid specimen may be contaminated with foreign substances which could adversely affect test results thereby resulting in erroneous diagnosis of a patient's symptoms through analysis of the collected blood specimen unless an evacuated collection container is utilized for receipt and storage of the specimen.
Having collected a blood/body fluid specimen in the syringe's body, the health care worker, then transfers that specimen into the blood/body fluid collection container. It is this step of the procedure which subjects the health care worker to the greatest hazard or risk. Recognizing the needle has now at least been in contact with, if not actually carrying a patient's blood/body fluid which must be considered as having infectious disease virus, the health care worker must now exercise extreme caution in all subsequent operations. Two of the most dangerous viruses that may be present in the blood/body fluid specimen are the HIV/AIDS and Hepatitis B or C strains. As previously noted, prior art closures members for collection containers are puncturable, and are only puncturable, by sharp-pointed needles.
The first step in effecting transfer of the specimen from the syringe to the collection container is insertion of the syringe's needle through the transverse end of the closure member in a generally axial direction relative to the collection container's tubular body. This presents a first instance where the technician may experience an accidental piercing of a finger by the needle, or perhaps another part of the hand that is holding the collection container, thereby becoming infected with a virus carried by the blood/body fluid specimen that has just been drawn. An accidental stick could also occur as a consequence of the health care worker making an error in physically manipulating the components while picking up a collection container and bringing it and the needle into proximate relationship to the collection container preparatory to inserting the needle into the container through the closure member.
A second instance when an accidental needle stick may occur is after ejecting the blood/body fluid sample from the syringe into the collection container and then withdrawing the needle from the closure member. The closure members for these collection containers is usually fabricated from an elastomeric material of a type that is self-resealable whereby it closes the opening previously made by the needle thereby maintaining the vacuum state in the collection container space that has not been filled with the just drawn blood/body fluid specimen. These closure members are usually formed from an elastomeric material tending to maintain a tight, compressive engagement with the exterior surface of the needle as is desired to assure the vacuum will be effectively maintained in the collection container. This also effectively prevents entrance into the container of ambient air containing gaseous materials and solid particles that would likely contaminate the blood/body fluid specimen. When the health care worker begins pulling the needle axially out of the closure member, considerable force must be applied to overcome the frictional force existing between the needle and the closure member. It is when the needle is nearly fully withdrawn from the closure member that a critical stage in the withdrawal operation is reached where one is likely to encounter an accidental needle stick to the finger or hand thereof. This results from the fact that as the tapered end of the needle exits through the closure member the frictional force rapidly diminishes since the surface area of the needle decreases due its tapered configuration; but, the health care worker tends to experience momentary loss of directional or speed control, or both, of the needle. This loss of control may often be of such extent as to cause an accidental sticking by the contaminated syringe's needle into a health care worker's finger on the hand holding the collection container.
A number of circumstances enter into effecting this loss of control with one major factor being that the health care worker has no accurate means of determining when the terminal end portion of the needle will exit the closure member. The terminal end portion of the needle is still within the collection container where it is concealed from view by the closure member which is invariably fabricated from an opaque material. As a result, the health care worker cannot precisely determine when the needle is in position to begin exiting the closure member and is not likely to be fully prepared to timely react appropriately to the unpredictable movement of the needle as it exits from the closure member. Another factor is the diminishing surface area of the needle in frictional engagement with the closure member as the terminal end of the needle passes through the membrane of the closure member. This results from the fact that the terminal end of the needle tapers to a sharp point thereby reducing the axially directed force necessary to effect its withdrawal. However, a health care worker is not aware of when a lesser force is required and does not reduce the extracting force resulting in an increase in the extracting speed of the needle, thus compounding the problem. Also, the health care worker is usually holding the syringe in a manner which provides minimal directional control over a needle that may be moving in an erratic fashion.
All blood/body fluid specimens drawn from patients are deemed to include infectious disease virus. Accordingly, the health care worker involved with drawing of blood/body fluids specimens, or their subsequent handling and processing, observe certain safety protocols which have been established to enhance minimization of transmission of these devastating diseases. This problem of becoming accidently infected is of no small significance when one considers the number of accidental needle sticks that occur annually along with the seriousness of the consequences that can result. A first and primary concern is the health of the health care worker who has incurred a needle stick. Soon after receiving a stick the health care worker must initiate precautionary procedures and ongoing monitoring to counteract the possibility of having become infected with a devastating, if not, deadly, virus.
An example of a prior art biological liquid container having what is designated as a safety closing device is disclosed in U.S. Pat. No. 5,433,716 granted Jul. 18, 1995 to Leopard, et al. That device includes two cooperating components of circular disc form disposed in superposed relationship over the open end of a container to which they are removably secured. One of discs identified by the numeral 4 remains on the container at the time of effecting transfer of a liquid into the container and is made of a perforable material but it is fabricated with a transversely extending incision identified by the numeral 8 that extends through the disc. This incision is formed in a manner whereby its opposing surfaces extend into contacting engagement thus forming a hermetic seal. The specification of this patent only describes use of sharpened "needle" for insertion through the incision in effecting a blood/body fluid drawing procedure.
Other known prior art disclosures and apparatus, whether patented or not, are all of a type which utilize a sharpened needle. Some of the patent disclosures refer to the device that is inserted through a container's closure member as being a "cannula". But, the drawings of those patents only show use of a sharp needle in effecting transfer of blood/body fluid to a collection container and their respective descriptions do not provide either a direct indication or even a remote suggestion that the cannula should or could be other than a sharp needle.